Читать книгу Predicting Heart Failure - Группа авторов - Страница 61

Dyspnea is a condition where the patient suffers from shortness of breath or sometimes difficulty in breathing. Labored breathing, tightness in the chest, heart palpitations, and wheezing are often the indications of a person experiencing dyspnea. It can occur after intense exercise or from traveling to a high altitude. However, it can be directly related to severe health conditions such as pneumonia, heart failure, or low blood pressure. Dyspnea on exertion can be a normal occurrence unless it accompanies an activity that can be considered to be within the tolerance limits of the individual.

Since dyspnea is often characterized by the subjective experience or sensation reported by the patient, it is quite distinguishable from tachypnea, hyperventilation, and hyperpnea, which refer to respiratory variations. The latter conditions exist irrespective of the patients’ subjective sensations. Tachypnea is an increase in the respiratory rate, which is indicated by rapid shallow or deep breathing, often unnoticed by the patient. Hyperventilation is the increased and rapid breathing that occurs due to an unbalance between inhalation and exhalation. The increased exhalation results in reduced carbon dioxide levels in the blood, which in turn leads to the symptoms such as dizziness, shortness of breath, etc. Hyperpnea is also a condition of deep breathing but not necessarily faster. The forced respiration causes the inhalation of an increased air volume and the respiratory rate can even stay within normal limits. This is an indication of the body’s demand for more oxygen. These medical conditions might not always be associated with dyspnea.

The sensation of breathlessness that occurs only in the specific posture of lying down is referred to as orthopnea. It can result in tightness in the chest that makes breathing uncomfortable. However, it subsides when the patient stands upright or sits down. Still, it might be a symptom of heart or lung disease. The presence of increased heart rate, wheezing, or nausea along with orthopnea is an indicator for heart failure. A condition that is closely related to orthopnea is paroxysmal nocturnal dyspnea. It is a sensation of shortness of breath that makes the patient wake up after 1 or 2 hours of sleep. Similar to orthopnea, this condition is usually relieved after getting back to the upright position.

Apart from the aforementioned conditions of breathing difficulties, there are two uncommon types of breathlessness: trepopnea and platypnea. Trepopnea is typically dyspnea or breathlessness in either lateral decubitus position. The shortness of breath when lying on the left side can be attributed to chronic heart diseases. On the other hand, breathlessness experienced while lying on the right side may be due to a lung disease or a major bronchus. Platypnea is the reverse condition of orthopnea. This refers to breathlessness that occurs in the upright position (sitting or standing) and gets improved when lying down.